From Fedora Project Wiki

Libraries and Applications

Many language- or domain-specific guidelines refer to "libraries", "modules", "plug-ins" or other terms specific to the language or domain. This is specifically important to package naming. Some applications may include libraries, and some libraries may include applications, so the distinction is not always clear.

Library or Application?

  • If the primary purpose of a package is to provide executables to be run by users, it SHOULD be packaged as an application. If it also includes libraries which may be imported or linked to by other code, see #Mixed Use Packages below.
  • If the primary purpose of a package is to provide libraries intended to be imported or loaded into other code, it is considered a library and MUST be packaged as such. If it contains utility programs that can be run by users as well, see #Mixed Use Packages below.

It is left to the packager to determine the primary purpose of a package. Often times upstream will already have done this with their choice of naming and that choice SHOULD be followed by the Fedora packager.

Mixed Use Packages

Many packages, regardless of their primary purpose, include both applications and libraries. In this case one or both SHOULD be packaged in subpackages in order to allow other applications to depend on only the library and not the associated application(s). Installing an application that depends on a library or service should not automatically pull in other applications associated with that library or service.

Application Independence

Applications SHOULD be installable independently whenever this is technically feasible. Packages that contain a visible .desktop file (a .desktop file that does not contain the line NoDisplay=true) SHOULD NOT have a Requires, Recommends, or Supplements on any other package containing a visible desktop file, directly or indirectly, unless the dependency is required for technical reasons or truly makes sense to have. For example, it would be reasonable for a video game level editor to require the associated video game in order to function, or for an application's plugin to require the associated application. But it would not be reasonable for an application that happens to use a database library to depend on a database management application associated with that library, or for an application that happens to use a particular programming language to depend on management tools associated with that programming language.

If a source package provides multiple desktop applications, those applications SHOULD be packaged in separate subpackages when feasible.